Conflict history based heuristic for constraint satisfaction problem solving

The variable ordering heuristic is an important module in algorithms dedicated to solve Constraint Satisfaction Problems (CSP), while it impacts the efficiency of exploring search space and size tree. It also exploits, often implicitly, structure instances. In this paper, we propose Conflict-History Search (CHS), a dynamic adaptive for CSP solving. based on failures considers temporality these throughout solving steps. exponential recency weighted average used estimate evolution hardness constraints search. experimental evaluation XCSP3 instances shows that integrating CHS solvers MAC (Maintaining Arc Consistency) BTD (Backtracking with Tree Decomposition) achieves competitive results improvements compared state-of-the-art heuristics. Beyond decision problem, show empirically constraint optimization problem (COP) can take advantage heuristic.